Waterborne vessel



Nov. 5, 1968 REDSHAW 3,408,821

WATERBORNE VESSEL med Aug. a, 19e@ 2 sheets-sheer 1 /Z/a/A MMM Nov. 5, 1968 1 REDSHAW WATERBORNE VESSEL 2 Sheets-Sheet Filed Aug.

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MM @M @wf ."1 @W United States Patent 3,408,821 WATERBORNE VESSEL Leonard Redshaw, Askam-in-Furness, England, assigner to Vickers Limited, London, England, a British company Filed Aug. 2, 1966, Ser. No. 569,617

Claims priority, application Great Britain, Aug. 10, 1965,

Claims. (Cl. 61-46.5)

ABSTRACT OF THE DISCLOSURE The disclosed waterborne or floatable vessel, primarily useful to be transported to a location where it is moored, comprises an upright column carrying a ballast chamber at or near its lower end, a superstructure mounted on the column for movement therealong between a lower position near the ballast chamber and an upper position at or near the upper end of the column. ln one form the upper portion of the column is of lesser cross-sectional area than the lower portion and a collar is provided on the upper portion along which the superstructure is movable and to which it may be attached. In another form, the upright column includes telescoping upper and lower sections and a buoyancy chamber carried by the lower end portion of the upper section.

Brief summary of invention This invention relates to waterborne vessels and is more particularly, though not exclusively, concerned with the provision of a generally improved vessel intended for use primarily as a stationary vessel, for example a floating radio station, or a meteorological and/or hydrographie station.

According to the present invention there is provided a waterborne vessel including an upright column which carn'es a ballast chamber positioned at or near the lower end of the column, a superstructure which is slidably mounted on the column for movement between a lower position adjacent the ballast chamber and an upper position at or near the upper end of the column and means for securing the superstructure in said upper position.

Although intended primarily for stationary use, the vessel is towable to the intended site, and to this end, the superstructure is slidably mounted on the column. In this way, the vessel can be towed through the water with the ballast chamber relatively unballasted so that the chamber itself lioats in the water, and with the superstructure positioned adjacent the ballast chamber. On reaching the site, the ballast chamber can be sunk and the superstructure raised to a position at or near the upper end of the column, in which it is well clear of the water, to convert the vessel into the operative condition. It will be appreciated that, in the towing condition, the vessel has a relatively shallow draft.

In order that the invention may be more fully understood, two constructions of waterborne vessel, in accordance with the invention and constructed for use as tioating radio stations, will now be described by way of example with reference to the accompanying drawings, in which,

FIGURE 1 shows an outline elevation of the first construction in the operative condition,

i FIGURE 2 shows a similar view of the second construction, and

FIGURE 3 shows an elevation of the second vessel but in the towing condition.

Referring now to FIGURE 1, the vessel consists of an upright column 1 which carries a ballast chamber 2 positioned at or near the lower end of the column and a superstructure 3 above the ballast chamber.

The ballast chamber, which forms the lowest part of the vessel, is a generally cylindrical body which is of all welded mild steel construction involving conventional ship-building practice. In the example under consideration, the ballast chamber is approximately feet in diameter and 30 feet in height. Conveniently a water-tight deck is arranged approximately 10 feet below the top of the chamber and the space below this deck sub-divided by radial bulkheads into eight separate ballast tanks arranged around a central chamber which may be used for illing and emptying the ballast tanks. The deck may contain a pump room from which ballasting operations are controlled and a compensating sea water ballast tank. In the particular construction being described, the ballast chamber weighs approximately 2,100 tons and also carries about 1,500 tons of solid ballast.

The column, which is also of all welded mild steel construction and is ring stiliened in a similar manner to that of a submarine pressure hull, extends upwards from the top of the ballast chamber, co-axially with the chamber, and consists of two sections 4, 5 of differing diameters connected by a tapered intermediate section 6. In the present example, the lower section 4 is of approximately feet in length and has an external diameter of about 30 feet, the length and diameter of the upper section 5 being approximately and 15 feet respectively. The diameter of the intermediate section tapers from that of the lower section to that of the upper section and this section is 15 feet approximately in length. The column of the vessel under consideration weighs about 600 tons.

The superstructure 3 is also a generally cylindrical body of, for example, 80 feet in diameter and 30 feet in height, and is constructed of aluminium alloy. The structure is slidably mounted on the column, for a purpose to be described later, so that relative axial sliding movement of the superstructure and the column may take place to move the superstructure between a lowered position adjacent the ballast chamber 2 (indicated in broken line in FIGURE 1) and a raised position at the top of the column. The superstructure 3 is therefore in the form of a collar having an internal diameter corresponding to the diameter of the lower section 4 of the column and, in order to position the superstructure co-axially with respect to the column when the superstructure is positioned on the upper section 5, the column carries an intermediate collar 7 which surrounds the upper section. The internal diameter of the intermediate collar corresponds to the diameter of the upper column section 5 and the radial depth of this collar corresponds to the difference in the respective radii of the upper and lower'sections.

The superstructure carries a radio mast (not shown) but this is positioned to one side of the superstructure so as to leave free the upper superstructure surface which is constructed as a landing deck for helicopters. The superstructure also incorporates radio equipment and a duct 11 is formed in the vessel to extend the full length thereof, the purpose of which is to enable a submarine'cable to be lead from the bottom of the vessel to the radio equipment in the superstructure. As an alternative to the submarine cable link the radio station may be equipped with the necessary equipment to enable the link to be made via a synchronous satellite, thus rendering the submarine cable unnecessary. The superstructure is itself buoyant and in the particular vessel being described weighs about 200 tons.

The vessel will normally be constructed in a shipyard using normal shipbuilding practice and techniques and it is convenient to build the ballast chamber and the lowermost part of the lower column section first, whereafter the construction of the superstructure may be commenced, around the centre column, on the upper deck of the ballast chamber. The erection of the remainder of the column would then take place. Alternatively, if desired, the superstructure may be erected after completion of the entire column.

The superstructure is thus initially positioned at the lower end of the column adjacent the ballast chamber, and it is in this condition that the vessel is towed out to the site. During this operation, the ballast chamber is relatively unballastcd so that it floats in the water although to give the required stability, permanent solid ballast may be added. It should be noted that the towing draught is relatively shallow and, as indicated at 8 in the drawing, is only approximately 24 feet. The aforementioned intermediate collar is, at this stage, positioned at the lower end of the upper column section to rest on the tapered intermediate section as indicated in broken line in FIGURE 1.

On arrival at the site, the vessel is positioned relatively to its moorings by the towing vessel or vessels. Flooding of the ballast chamber is now effected, which causes the ballast chamber to sink This causes the column and in turn the superstructure to be lowered with the result that the superstructure becomes supported by its own buoyancy Iand the centre column moves down through the superstructure central aperture. Ballast is added until the superstructure 3 engages the intermediate collar 7 whereafter the superstructure is attached to this collar by suitable means indicated diagrammatically at 3. In order to facilitate attachment to the vessel of the necessary moorings, the water ballast in the ballast chamber is now reduced to raise the whole vessel so that the superstructure is raised clear of the water. After transfer of the moorings and any other lines from attendant vessels to the radio station vessel, water ballast is added to the ballast chamber firstly to lower the superstructure and collar into the water again and secondly to draw the centre column even further down through the superstructure. This operation is continued until the superstructure and collar become positioned at the top of the column at which position they are secured to the column, preferably automatically by means of a self-locking mechanism indicated diagrammatically at 7.

Finally water ballast is removed from the ballast charnber to raise the whole vessel until the required water line is reached (indicated at 9 in FIGURE 1). The vessel may have, for example, a final draft of approximately 210 feet with the top deck of the superstructure lying some 90 feet above the water level.

The foregoing mooring procedure is quite reversible should access to the mooring attachments which are preferably at the junction of the two column sections and therefore below the water line, be required, or towing of the vessel to the mainland for drying docking, be necessary.

It was previously mentioned that the superstructure has its own buoyancy and in fact in the particular vessel being described, the superstructure has a reserve buoyancy (that is an excess of available buoyancy over its weight) of `approximately 2,200 tons. Therefore, should the underwater portion of the vessel become damaged while on station so that its buoyancy be lost and the whole vessel be in danger of foundering, the superstructure may bel detached from the central column by release means provided therefor so that it can float on its own. This is important, since apart from providing a stable vessel for the crew of the vessel to remain on, a substantial part of the somewhat expensive radio equipment carried in the vessel would be saved as this is incorporated in the superstructure.

Referring now to FIGURES 2 and 3, the second construction of vessel, is of similar general construction to the above described vessel but with certain modications. Here the column 12 is composed of two, telescoped, sections 13 and 14, the lower section projecting into the upper section, and each section carries, at its lower end, a chamber, the chambers associated with the two column sections being referenced 15 and 16 respectively.

The lower chamber 15 which is of all welded mild steel construction may, for example, be approxi-mately horizontal water tight deck and radial bulkheads. The

lower column section projects from this lower chamber, to rise to a height of about feet above the top of the chamber and has a diameter of approximately 16 feet` Conveniently this section contains a pump room at its base.

The upper chamber 16 which is a buoyancy chamber, has approximately the same 4dimensions as the lower one and likewise carries a column section projecting therefrom, this section being the upper section 14 of the complete column. The upper column section conveniently projects some feet above the top of the upper chamber and is of a diameter of about 20 feet. As mentioned above, the respective column sections are arranged for telescopic action, and, in the contracted condition of the column, the lower section is housed within the upper section, with the chamber 16 positioned on top of the chamber 15. A system of guides and rollers indicated at 18 is therefore installed between the two columns to ensure a 'smooth telescopic action and means are provided for securing the sections in the extended condition, the means including a taper 19 at the Lbase of the upper column for engagement with a corresponding taper 21 at the top of the lower section to form a rigid column in the operating condition. The tapers will in practice be positioned so as not to interfere with the guide system 18.

The superstructure 17 is of the same general construction as for the rst described vessel and is slidably mounted on the upper column section 14. The internal diameter of this part of the vessel is, however, reduced to suit the `diameter of the upper column section, there being no intermediate collar in this case.

Construction of this vessel may generally follow the pattern already described, using conventional shipyard techniques. The lower chamber 15 with part of its column section may be assembled first and on top of it, the upper chamber 16 with the lower part of the upper column section. The superstructure may then be erected in a position surmounting the upper chamber and surrounding the column, whereafter erection of the remainder of the two column sections Imay then proceed.

Towing to the intended site is effected with the upper chamber floating in the water and the column sections telescoped together so that the lower chamber is positioned immediately under the upper chamber, as shown in FIGURE 3. As for the vessel shown in FIGURE 1, the superstructure is in a lowered position resting on the upper surface of the upper chamber.

On reaching the site, an initial ballasting operation is carried out which involves admission of water ballast to the lower chamber 15 to sin-k this chamber until the lower column section has been withdrawn from the upper column section sutiiciently to engage the previously mentioned tapers which render the component column sections rigid with one another. Ballasting is now continued to sink the lower chamber further and to submerge the upper chamber 16 until the superstructure 17 becomes waterborne and the upper column section has been drawn `downwards through the centre of the superstructure through a certain distance. The superstructure is then locked, by suitable means 17', to the column whereafter unballa'sting is carried out to raise the superstructure above the water so that moorings can be attached as for the previously described vessel. Further ballast is now added until the top of the column aligns with the helicopter iiight deck when the superstructure becomes locked to the column section 14 by means of the automatic locking mechanism 17' which is provided :for this purpose. The mechanism 17 includes the device, mentioned above, for locking the superstructure to the column in a position intermediate of the length of the upper section. Finally, by unballasting, the superstructure is raised from the water until the desired operating draught (indicated in FIGURE 2) is achieved, this being about 200 feet. The towing draught (see FIGURE 3) is approximately 30 feet.

Likewise for this vessel the foregoing procedure may tbe reversed to enable periodic inspection of the underwater portion of the hull to 'be accomplished and, should a major overall be necessary, the vessel may be restored to its towing condition and returned to the mainland.

Whilst the second described vessel is possibly more mechanically complex than the rst vessel, its overall height, in the contracted condition of the column, is smaller than the column height of the rst vessel, and the vessel may therefore be assembled using dockside craneage wereas the increased height of the one-piece column of the rst `described vessel renders it necessary to use drill-rigr techniques in erecting the upper column section of this vessel.

The provision of a Islidably mounted superstructure on the column in both the described vessels enables the column to be of considerable length in relation to its diameter, which in turn provides the vessel with a good draught in its operating condition leading to good stability. Moreover the heave amplitude, and angle of inclination of the buoy, caused by the action of wind and wave forces is greatly minimised by the design of the vessel. On the other hand when the vessel is required to be towed, a shallow `draught is obviously desirable and the slidable mounting of the lsuperstructure enables the draft to be considerably reduced.

What is claimed is:

1. In a floatable waterborne vessel, including an upright column carrying a floodable ballast chamber adjacent its lower end and a buoyant superstructure mounted on the column for movement therealong between a lower position near the ballast chamber and an upper position adjacent the upper end of the column, the improvement wherein the vessel consists of a single upright column provided with a ballast chamber and buoyant superstructure which are of relatively large cross-sectional area compared to that of the upright column, the vessel having a structure such that the ballast chamber is lloodable to convert the vessel from a transit condition in which the ballast chamber oats in the water with the superstructure in its lower position on the column, to an intermediate condition in which the ballast chamber is sunk in the water to draw the column down through the buoyant superstructure as it floats in the water until the upper end of the column is at the position of the superstructure, means for securing the superstructure to the upper end portion of the column when the vessel is in said intermediate condition with the superstructure floating in the water and the ballast chamber and remainder of the column submerged in the water, said ballast chamber being partially unballastable at its sunken position to raise the column in the water and elevate the superstructure to a position clear of the water thereby converting the vessel to an operational condition buoyantly supported by the water.

2. In a waterborne vessel including an upright column carrying a ballast chamber positioned at or near its lower end, a superstructure mounted on the column for movement therealong between a lower position near the ballast chamber and an upper position at or near the upper end of the column, and means for Securing the superstructure in said upper position', the improvement wherein the column is composed of two main sections comprising a lower section and an upper section of smaller diameter than the lower section, the vessel further including a collar slidably mounted on said upper section and which is of a radial depth corresponding to the difference in the respective radii of the upper and lower sections of the column, and wherein said securing means includes means for securing the superstructure to the collar and means for securing the collar to the column at or near the upper end thereof.

3. In a waterborne vessel including an upright column carrying a ballast chamber positioned at or near its lower end, a superstructure mounted on the column for movement therealong between a lower position above and near the ballast chamber and an upper position at or near the upper end of the column, the improvement wherein the column is composed of two sections upper and lower arranged for telescopic action with the lower section projecting into the upper section, said lower section carrying said ballast chamber at its lower end, a buoyancy chamber disposed on the column between the ballast chamber and the superstructure, and means for securing the superstructure to the upper column section.

4. A vessel as claimed in claim 3, wherein the bouyancy chamber is carried on the lower portion of the upper column section.

5. A vessel as claimed in claim 3, wherein the column incorporates a system of guides and rollers to assist telescopic action between the sections and wherein the Sections are provided with means incorporating cooperating tapered members on the respective sections for securing the sections in the extended condition.

References Cited UNITED STATES PATENTS 3,086,367 4/1963 Foster 61-46.5 X 3,118,283 1/1964 True et al. 61-465 3,246,475 4/ 1966 vBooth et al. 61-46.5

FOREIGN PATENTS 991,247 5/ 1965 Great Britain.

JACOB SHAPIRO, Primary Examiner. 

